Commit 9b96c5aa authored by Cianciosa, Mark's avatar Cianciosa, Mark
Browse files

Reduce cases like (a/b)^c*b^d and it's variants.

parent cfe9453a

graph_framework/arithmetic.hpp

+35 −0
Original line number Diff line number Diff line
@@ -1078,6 +1078,41 @@ namespace graph { 
                }

            }



            auto lpd = divide_cast(this->left->get_power_base());

            if (lpd.get()) {

//  (a/b)^c*b^d -> a^c*b^(c-d)

                if (lpd->get_right()->is_power_base_match(this->right)) {

                    return pow(lpd->get_left(), this->left->get_power_exponent()) *

                           pow(this->right->get_power_base(),

                               this->right->get_power_exponent() -

                               this->left->get_power_exponent());

                }

//  (b/a)^c*b^d -> b^(c+d)/a^c

                if (lpd->get_left()->is_power_base_match(this->right)) {

                    return pow(this->right->get_power_base(),

                               this->right->get_power_exponent() +

                               this->left->get_power_exponent()) /

                           pow(lpd->get_right(), this->left->get_power_exponent());

                }

            }

            auto rpd = divide_cast(this->right->get_power_base());

            if (rpd.get()) {

//  b^d*(a/b)^c -> a^c*b^(c-d)

                if (rpd->get_right()->is_power_base_match(this->left)) {

                    return pow(rpd->get_left(), this->right->get_power_exponent()) *

                           pow(this->left->get_power_base(),

                               this->left->get_power_exponent() -

                               this->right->get_power_exponent());

                }

//  b^d*(b/a)^c -> b^(c+d)/a^c

                if (rpd->get_left()->is_power_base_match(this->left)) {

                    return pow(this->right->get_power_base(),

                               this->right->get_power_exponent() +

                               this->right->get_power_exponent()) /

                           pow(rpd->get_right(), this->right->get_power_exponent());

                }

            }



//  Exp(a)*Exp(b) -> Exp(a + b)

            auto le = exp_cast(this->left);

            auto re = exp_cast(this->right);

graph_tests/arithmetic_test.cpp

+15 −0
Original line number Diff line number Diff line
@@ -975,6 +975,21 @@ template<typename T> void test_multiply() { 
    assert(graph::pow_cast(common_base_cast4->get_right()).get() &&

           "Expected power cast on the right.");



//  (a/b)^c*b^d -> a^c*b^(c-d)

    auto divide_pow = graph::pow(v2/v1, two)*graph::pow(v1, two);

    assert(divide_pow->is_power_base_match(v2) && "Expected the v2 variable.");

//  (b/a)^c*b^d -> b^(c+d)/a^c

    auto divide_pow2 = graph::pow(v1/v2, two)*graph::pow(v1, two);

    assert(graph::divide_cast(divide_pow2).get() &&

           "Expected a divide node.");

//  b^d*(a/b)^c -> a^c*b^(c-d)

    auto divide_pow3 = graph::pow(v1, two)*graph::pow(v2/v1, two);

    assert(divide_pow3->is_power_base_match(v2) && "Expected the v2 variable.");

//  b^d*(b/a)^c -> b^(c+d)/a^c

    auto divide_pow4 = graph::pow(v1, two)*graph::pow(v1/v2, two);

    assert(graph::divide_cast(divide_pow4).get() &&

           "Expected a divide node.");



//  Test node properties.

    assert(two_times_three->is_constant_like() && "Expected a constant.");

    assert(!two_times_three->is_all_variables() && "Did not expect a variable.");